CN107525725B - Method and system for detecting fatigue life of aluminum alloy for railway vehicle - Google Patents
Method and system for detecting fatigue life of aluminum alloy for railway vehicle Download PDFInfo
- Publication number
- CN107525725B CN107525725B CN201710575850.8A CN201710575850A CN107525725B CN 107525725 B CN107525725 B CN 107525725B CN 201710575850 A CN201710575850 A CN 201710575850A CN 107525725 B CN107525725 B CN 107525725B
- Authority
- CN
- China
- Prior art keywords
- test
- aluminum alloy
- detection frequency
- applicability
- detection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M17/00—Testing of vehicles
- G01M17/08—Railway vehicles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
Abstract
The invention provides a method and a system for detecting the fatigue life of an aluminum alloy for a railway vehicle, wherein the detection method comprises the following steps: acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle; carrying out a fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle; wherein the first detection frequency is higher than the second detection frequency; and acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle. The invention effectively and reliably shortens the fatigue test period of the new section for the train body of the high-speed train, greatly reduces the test cost, reduces the technical preparation period of new products, and provides guarantee for the research and development of new train types such as the existing motor train unit.
Description
Technical Field
The invention relates to the technical field of rail transit, in particular to a method and a system for detecting the fatigue life of an aluminum alloy for a rail vehicle.
Background
The rail transit system is a transit system which uses vehicles to run on fixed guide rails in cities and is mainly used for urban passenger transport, and the rail vehicles in the rail transit system are main arteries for passenger flow transportation and are also city lifeline projects and are directly related to travel, work, shopping and life of urban residents. The aluminum alloy for the rail vehicle and the welded joint thereof of the rail vehicle are indispensable key materials and parts of the rail vehicle, and whether the fatigue life of the aluminum alloy for the rail vehicle and the welded joint thereof can be accurately known is the key for determining that the rail vehicle can safely and reliably run.
The standard fatigue test of aluminum alloy (7 series and 6 series) for railway vehicles and welding joints thereof is a procedure which must be carried out before the production of trains to test the quality of materials and the welding joints thereof, the current fatigue test is carried out by adopting the frequency of 10-20Hz, and the low-frequency test has obvious defects, mainly shows that the efficiency is low, the period is long, and the normal production and the supply period of the trains are often influenced.
Therefore, how to design a fatigue life detection method capable of shortening the detection period and improving the detection efficiency is an urgent problem to be solved.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the method and the system for detecting the fatigue life of the aluminum alloy for the railway vehicle, which effectively and reliably shorten the fatigue test period of the new section for the high-speed train body, greatly reduce the test cost, shorten the technical preparation period of new products and provide guarantee for the research and development of new train types such as the existing motor train unit.
In order to solve the technical problems, the invention provides the following technical scheme:
in a first aspect, the present invention provides a method for detecting fatigue life of an aluminum alloy for a railway vehicle, the method comprising:
acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle;
carrying out a fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle;
wherein the first detection frequency is higher than the second detection frequency;
and acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle.
Further, the first detection frequency is 100Hz to 130 Hz.
Further, the acquiring a first detection frequency for performing fatigue life detection on the aluminum alloy for the rail vehicle includes:
determining a plurality of alternative detection frequencies, wherein the value of each alternative detection frequency is higher than that of the second detection frequency;
sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test;
and performing a second applicability test on the aluminum alloy for the rail vehicle at the second detection frequency to obtain an applicability test result of the second applicability test;
comparing the applicability test result of each of the first applicability tests with the applicability test result of the second applicability test;
and if the difference value between the applicability test result of a certain first applicability test and the applicability test result of the second applicability test is smaller than a preset value, determining the alternative detection frequency corresponding to the applicability test result of the first applicability test as the first detection frequency.
Further, the first suitability test and the second suitability test each include:
the method comprises the following steps of (1) carrying out an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, a fatigue fracture characteristic test of the material base metal and the welding joint and a fatigue load test;
accordingly, the suitability test results include:
the energy conversion rule, the temperature evolution curve, the fatigue life of the material base metal and the welding joint, the fatigue fracture characteristics of the material base metal and the welding joint, and the fatigue life under the fatigue load.
Further, the aluminum alloy for a railway vehicle is a 7-series aluminum alloy or a 6-series aluminum alloy.
In another aspect, the present invention further provides a system for detecting fatigue life of an aluminum alloy for a rail vehicle, the system comprising:
the first detection frequency acquisition module is used for acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle;
the fatigue load test module is used for carrying out a fatigue load test at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle;
wherein the first detection frequency is higher than the second detection frequency;
and the fatigue life detection report acquisition module is used for acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle.
Further, the first detection frequency is 100Hz to 130 Hz.
Further, the first detection frequency obtaining module includes:
the alternative detection frequency determining unit is used for determining a plurality of alternative detection frequencies, and the value of each alternative detection frequency is higher than that of the second detection frequency;
the first applicability test unit is used for sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test;
the second applicability test unit is used for carrying out a second applicability test on the aluminum alloy for the railway vehicle under the second detection frequency to obtain an applicability test result of the second applicability test;
an applicability test result comparing unit for comparing an applicability test result of each of the first applicability tests with an applicability test result of the second applicability test;
and the first detection frequency determining unit is used for determining the alternative detection frequency corresponding to the applicability test result of the first applicability test as the first detection frequency when the difference value between the applicability test result of the first applicability test and the applicability test result of the second applicability test is smaller than a preset value.
Further, the first suitability test and the second suitability test each include:
the method comprises the following steps of (1) carrying out an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, a fatigue fracture characteristic test of the material base metal and the welding joint and a fatigue load test;
accordingly, the suitability test results include:
the energy conversion rule, the temperature evolution curve, the fatigue life of the material base metal and the welding joint, the fatigue fracture characteristics of the material base metal and the welding joint, and the fatigue life under the fatigue load.
Further, the aluminum alloy for a railway vehicle is a 7-series aluminum alloy or a 6-series aluminum alloy.
According to the technical scheme, the method and the system for detecting the fatigue life of the aluminum alloy for the railway vehicle comprise the following steps: acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle; carrying out a fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle; wherein the first detection frequency is higher than the second detection frequency; acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle; the invention adopts the high-frequency rapid test technology for the aluminum alloy for the rail vehicle and the welding joint thereof to completely or partially replace the original low-frequency test method, solves the problems of long period and low efficiency of the original low-frequency fatigue test, effectively and reliably shortens the fatigue test period of the new section for the high-speed train body, greatly reduces the test cost, reduces the preparation period of new product technology, and provides guarantee for the research and development of new train types such as the existing motor train unit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic flow chart of the method for detecting fatigue life of aluminum alloy for railway vehicles according to the present invention;
FIG. 2 is a schematic flow chart of step 100 of the fatigue life detection method of the present invention;
FIG. 3a) is a schematic diagram of the high-frequency fatigue test temperature characteristic curve of the aluminum alloy base material for the track when the pressure is 120 MPa;
FIG. 3b) is a schematic view of the high-frequency fatigue test temperature characteristic curve of the aluminum alloy base material for the rail when the pressure is 130 MPa;
FIG. 3c) is a schematic view of the high-frequency fatigue test temperature characteristic curve of the aluminum alloy base material for the rail when the pressure is 140 MPa;
FIG. 3d) is a schematic diagram of the high-frequency fatigue test temperature characteristic curve of the aluminum alloy base material for the track when the pressure is 150 MPa;
FIG. 3e) is a schematic diagram of the high-frequency fatigue test temperature characteristic curve of the aluminum alloy base material for the track when the pressure is 160 MPa;
FIG. 4a) is a schematic view showing a comparison of low-frequency and high-frequency fatigue lives of the 6-series aluminum alloy base material of the present invention;
FIG. 4b) is a comparative plot of low frequency, high frequency fatigue life for a 6 series aluminum alloy weldment of the present invention;
FIG. 4c) is a schematic view showing a comparison of low-frequency and high-frequency fatigue lives of the base material of the 7-series aluminum alloy of the present invention;
FIG. 4d) is a schematic comparison of the low frequency and high frequency fatigue life of a 7-series aluminum alloy weldment of the present invention;
FIG. 5a) is a schematic view of fracture of the 6-series aluminum alloy base material of the present invention at different frequencies;
FIG. 5b) is a schematic view of fracture of a 6-series aluminum alloy weldment of the present invention at different frequencies;
FIG. 5c) is a schematic view of a fracture of the base material of the 7-series aluminum alloy of the present invention at different frequencies;
FIG. 5d) is a schematic view of fractures of a 7-series aluminum alloy weldment of the present invention at different frequencies;
FIG. 6 is a schematic structural view of a fatigue life detecting system for an aluminum alloy for a railway vehicle according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses a specific implementation manner of a method for detecting the fatigue life of an aluminum alloy for a railway vehicle, and referring to fig. 1, the method for detecting the fatigue life of the aluminum alloy for the railway vehicle specifically comprises the following steps:
step 100: a first detection frequency for performing fatigue life detection on the aluminum alloy for the rail vehicle is acquired.
In the above steps, a plurality of candidate detection frequencies are set according to an actual application scene, and the plurality of candidate detection frequencies are screened through a second detection frequency (10-20Hz) commonly used in the prior art, so that a suitable candidate detection frequency is determined as a first detection frequency. It will be appreciated that the suitable candidate detection frequencies may not be unique, and that the first detection frequency may be a range of values when the suitable candidate detection frequencies are not unique. For example, if all candidate detection frequencies between 100Hz and 130Hz are suitable candidate detection frequencies, the first detection frequency is any value between 100Hz and 130 Hz. It is understood that the aluminum alloy for railway vehicles is a 7-series aluminum alloy or a 6-series aluminum alloy.
Step 200: carrying out a fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle; wherein the first detection frequency is higher than the second detection frequency.
In the above step, the performing a fatigue load test on the aluminum alloy for a railway vehicle at the first detection frequency, or at the first detection frequency and a preset second detection frequency specifically includes: according to the practical application condition, carrying out all test items in the fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency; or; and carrying out a part of test items in the fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency, and carrying out another part of test items in the fatigue load test on the aluminum alloy for the railway vehicle at a preset second detection frequency.
Step 300: and acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to the fatigue life detection result of the aluminum alloy for the railway vehicle.
From the above description, it can be seen that the embodiments of the present invention provide a method for detecting fatigue life of an aluminum alloy for a rail vehicle, and the aluminum alloy for a rail vehicle and a welded joint thereof are subjected to a high-frequency rapid test technology to completely or partially replace an original low-frequency test method, so that the problems of long period and low efficiency of an original low-frequency fatigue test are solved, and a fatigue test detection period is effectively and reliably shortened.
The second embodiment of the present invention discloses a specific implementation manner of step 100 in the above fatigue life detection method, and referring to fig. 2, the step 100 specifically includes the following contents:
step 101: and determining a plurality of alternative detection frequencies, wherein the value of each alternative detection frequency is higher than that of the second detection frequency.
Step 102: and sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test.
Step 103: and carrying out a second applicability test on the aluminum alloy for the railway vehicle under the second detection frequency to obtain an applicability test result of the second applicability test.
Step 104: comparing the applicability test result of each of the first applicability tests with the applicability test result of the second applicability test;
if the difference value between the applicability test result of a certain first applicability test and the applicability test result of the second applicability test is smaller than a preset value, entering step 105;
otherwise, return to step 101 to re-determine the alternative detection frequency.
Step 105: and determining the candidate detection frequency corresponding to the applicability test result of the first applicability test as the first detection frequency.
In the above step, 4, the detection method according to claim 3, wherein each of the first suitability test and the second suitability test includes:
the test method comprises an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, a fatigue fracture characteristic test of the material base metal and the welding joint and a fatigue load test.
Accordingly, the suitability test results include:
the energy conversion rule, the temperature evolution curve, the fatigue life of the material base metal and the welding joint, the fatigue fracture characteristics of the material base metal and the welding joint, and the fatigue life under the fatigue load.
It can be understood that the determination of energy conversion, temperature evolution curve, fatigue life and fracture during fatigue at different frequencies uses a first detection frequency:
forming a plurality of test frequency groups by the different alternative test frequencies and the second test frequency respectively;
1. under each test frequency group, respectively testing the influence on the fatigue life of different metals and alloys and the energy conversion in the fatigue test process, if the result of a certain test frequency group is as follows: if the aluminum alloy (7 series and 6 series) materials for the high-speed train have the same energy conversion rule in the fatigue process under different frequencies, determining that the alternative detection frequency in the group meets one of the requirements of the first detection frequency;
2. under each test frequency set, the temperature change measurement is respectively carried out on the aluminum alloy (7 series and 6 series) materials and the welding joints thereof, if the result of a certain test frequency set is as follows: if the temperature evolution curves of the two materials in the fatigue test process have similar characteristics, determining that the alternative detection frequency in the group meets the second requirement of the first detection frequency;
3. in each test frequency set, the fatigue test is respectively carried out on the base metal of the aluminum alloy (7 series and 6 series) material and the welding joint, and if the result of a certain test frequency set is as follows: the fatigue life difference is not large; determining that the alternative detection frequencies in the set meet the three requirement of the first detection frequency;
4. under each test frequency group, analyzing high-frequency and low-frequency fatigue fractures of the base metal of the aluminum alloy (7 series and 6 series) material and the welding joint, and comparing and analyzing a fracture mechanism, fatigue crack initiation and expansion characteristics, wherein if the result of a certain test frequency group is as follows: the fatigue striation widths at different frequencies are comparable, if the results for a certain set of test frequencies are: if the materials show similar fracture characteristics under the two frequencies, determining that the alternative detection frequency in the group meets the requirement of the first detection frequency;
5. for the base material of the aluminum alloy (7 series and 6 series) material for the rail vehicle and the welded joint, the high frequency fatigue (100Hz to 130Hz) load is used instead of the low frequency (20Hz) fatigue load for each test frequency set, and if the result of a certain set of test frequency sets is: determining that the candidate detection frequency in the group meets the requirement of the first detection frequency if the fatigue life does not change significantly;
and if the alternative detection frequency in a certain group of test frequency groups meets the requirements of all the first detection frequencies, determining the alternative detection frequency as the first detection frequency.
From the above description, the embodiment of the invention provides a method for detecting the fatigue life of the aluminum alloy for the railway vehicle, which can accurately obtain the high-frequency detection frequency suitable for detecting the fatigue life of the aluminum alloy for the railway vehicle, and provides an accurate data base for the subsequent fatigue life detection.
For further explaining the scheme, the invention also provides a specific implementation mode for verifying the feasibility of the method for detecting the fatigue life of the aluminum alloy for the railway vehicle by using the first detection frequency (high frequency 100 Hz-130 Hz) to replace the second detection frequency (low frequency 20Hz), and the specific method for verifying the feasibility specifically comprises the following steps:
compared research is carried out on the fatigue performance of the aluminum alloy (7 series and 6 series) material for the high-speed train and the welding joint thereof under low frequency and high frequency, and the feasibility of replacing low frequency with high frequency is demonstrated from the energy conversion, the temperature evolution curve, the fatigue life and the fracture analysis in the fatigue process under different frequencies.
1. Through researching the influence of frequency on the fatigue life of different metals and alloys and energy conversion in the fatigue test process, the aluminum alloy (7 series and 6 series) materials for high-speed trains have the same energy conversion rule in the fatigue process under different frequencies, and a theoretical basis is provided for the invention.
2. In order to solve the problem that temperature change in the fatigue test process has great influence on the fatigue life, the temperature evolution curve in the fatigue test process can represent the influence of frequency on the fatigue life. The temperature changes of the aluminum alloy (7 series and 6 series) materials and the welding joints thereof in the low-frequency and high-frequency test processes are measured, so that the temperature evolution curves of the two materials in the low-frequency and high-frequency fatigue test processes are proved to have similar characteristics, and the fatigue performance of the materials cannot be influenced by the temperature change of a test piece under the high-frequency fatigue load, and the temperature changes are shown in figures 3a) to 3 e).
4. By performing fatigue tests on the base metal of the aluminum alloy (7 series and 6 series) material and the welded joint at different frequencies, the fatigue life difference is compared, and the fatigue life difference is found to be small at different frequencies, see fig. 4a) to 4 d).
5. By analyzing the high-frequency and low-frequency fatigue fractures of the base metal of the aluminum alloy (7 series and 6 series) material and the welded joint and comparing and analyzing the fracture mechanism, the fatigue crack initiation and propagation characteristics, the fatigue striation widths under different frequencies are equivalent, and the materials under the two frequencies show similar fracture characteristics, see fig. 5a) to 5 d).
6. The base material and welded joint of the aluminum alloy (7-series and 6-series) material for rail vehicles were tested using a high-frequency fatigue (100Hz to 130Hz) load instead of a low-frequency (20Hz) fatigue load, and the fatigue life did not change significantly.
From the above description, the method for verifying feasibility realizes that the high-frequency fatigue load test replaces the existing low-frequency fatigue load test by researching the fatigue fracture mechanism and the fatigue performance data corresponding rule of the base metal and the welding joint thereof under high frequency and low frequency; providing a test rule of a high-frequency test, and obtaining an effective S-N curve which is the same as a low frequency by utilizing the fatigue performance of the high-frequency test machine on the base metal and the welding joint of 6N01 and 7N01, wherein the load frequency is 100-130Hz or more; the fatigue test is carried out by adopting high frequency, so that the fatigue test period of the new section for the train body of the high-speed train is greatly shortened, and the guarantee is provided for the research and development of the existing new train types such as the motor train unit and the like.
The third embodiment of the present invention discloses a specific implementation manner of a fatigue life detection system for an aluminum alloy for a rail vehicle, which can implement the above fatigue life detection method, and referring to fig. 6, the fatigue life detection system specifically includes the following contents:
a first detection frequency acquisition module 10, configured to acquire a first detection frequency for performing fatigue life detection on an aluminum alloy for a rail vehicle;
the fatigue load testing module 20 is configured to perform a fatigue load test on the aluminum alloy for the rail vehicle at the first detection frequency, or at the first detection frequency and a preset second detection frequency, so as to obtain a fatigue life detection result of the aluminum alloy for the rail vehicle; wherein the first detection frequency is higher than the second detection frequency;
and the fatigue life detection report acquisition module 30 is used for acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle.
Wherein the first detection frequency is 100Hz to 130 Hz.
The first detection frequency acquisition module includes:
the alternative detection frequency determining unit is used for determining a plurality of alternative detection frequencies, and the value of each alternative detection frequency is higher than that of the second detection frequency;
the first applicability test unit is used for sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test;
the second applicability test unit is used for carrying out a second applicability test on the aluminum alloy for the railway vehicle under the second detection frequency to obtain an applicability test result of the second applicability test;
an applicability test result comparing unit for comparing an applicability test result of each of the first applicability tests with an applicability test result of the second applicability test;
and the first detection frequency determining unit is used for determining the alternative detection frequency corresponding to the applicability test result of the first applicability test as the first detection frequency when the difference value between the applicability test result of the first applicability test and the applicability test result of the second applicability test is smaller than a preset value.
Wherein, first suitability test and second suitability test all include:
the method comprises the following steps of (1) carrying out an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, a fatigue fracture characteristic test of the material base metal and the welding joint and a fatigue load test;
accordingly, the suitability test results include:
the energy conversion rule, the temperature evolution curve, the fatigue life of the material base metal and the welding joint, the fatigue fracture characteristics of the material base metal and the welding joint, and the fatigue life under the fatigue load.
Wherein the aluminum alloy for the railway vehicle is a 7-series aluminum alloy or a 6-series aluminum alloy.
From the above description, the embodiment of the invention provides a fatigue life detection system for an aluminum alloy for a railway vehicle, which completely or partially replaces the original low-frequency test method by adopting a high-frequency rapid test technology for the aluminum alloy for the railway vehicle and a welding joint thereof, overcomes the problems of long period and low efficiency of the original low-frequency fatigue test method, effectively and reliably shortens the fatigue test period of a new section for a high-speed train body, and provides guarantee for the research and development of the existing new train types such as a motor train unit.
The above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (2)
1. A method for detecting fatigue life of an aluminum alloy for a railway vehicle, the method comprising:
acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle; the aluminum alloy for the railway vehicle is a 7-series aluminum alloy or a 6-series aluminum alloy;
carrying out a fatigue load test on the aluminum alloy for the railway vehicle at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle;
wherein the first detection frequency is higher than the second detection frequency, the first detection frequency is 100Hz to 130Hz, and the second detection frequency is 10Hz to 20 Hz;
acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle;
the acquiring a first detection frequency for performing fatigue life detection on an aluminum alloy for a rail vehicle includes:
determining a plurality of alternative detection frequencies, wherein the value of each alternative detection frequency is higher than that of the second detection frequency;
sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test;
and performing a second applicability test on the aluminum alloy for the rail vehicle at the second detection frequency to obtain an applicability test result of the second applicability test;
comparing the applicability test result of each of the first applicability tests with the applicability test result of the second applicability test;
if the difference value between the applicability test result of a certain first applicability test and the applicability test result of the second applicability test is smaller than a preset value, determining the alternative detection frequency corresponding to the applicability test result of the first applicability test as the first detection frequency;
the first suitability test and the second suitability test both comprise:
the method comprises the following steps of (1) carrying out an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, and a fatigue fracture characteristic test of the material base metal and the welding joint under fatigue load;
accordingly, the suitability test results include:
energy conversion rule, temperature evolution curve, fatigue life of material base metal and welding joint, and fatigue fracture characteristics of material base metal and welding joint.
2. A fatigue life detection system for an aluminum alloy for a railway vehicle, the detection system comprising:
the first detection frequency acquisition module is used for acquiring a first detection frequency for detecting the fatigue life of the aluminum alloy for the railway vehicle; the aluminum alloy for the railway vehicle is a 7-series aluminum alloy or a 6-series aluminum alloy;
the fatigue load test module is used for carrying out a fatigue load test at the first detection frequency or at the first detection frequency and a preset second detection frequency to obtain a fatigue life detection result of the aluminum alloy for the railway vehicle;
wherein the first detection frequency is higher than the second detection frequency, the first detection frequency is 100Hz to 130Hz, and the second detection frequency is 10Hz to 20 Hz;
the fatigue life detection report acquisition module is used for acquiring a fatigue life detection report of the aluminum alloy for the railway vehicle according to a fatigue life detection result of the aluminum alloy for the railway vehicle;
the first detection frequency acquisition module includes:
the alternative detection frequency determining unit is used for determining a plurality of alternative detection frequencies, and the value of each alternative detection frequency is higher than that of the second detection frequency;
the first applicability test unit is used for sequentially carrying out first applicability tests on the aluminum alloy for the railway vehicle under each alternative detection frequency to obtain applicability test results of each first applicability test;
the second applicability test unit is used for carrying out a second applicability test on the aluminum alloy for the railway vehicle under the second detection frequency to obtain an applicability test result of the second applicability test;
an applicability test result comparing unit for comparing an applicability test result of each of the first applicability tests with an applicability test result of the second applicability test;
a first detection frequency determining unit, configured to determine, when a difference between a first applicability test result of a certain first applicability test and a second applicability test result of the second applicability test is smaller than a preset value, an alternative detection frequency corresponding to the first applicability test result as the first detection frequency;
the first suitability test and the second suitability test both comprise:
the method comprises the following steps of (1) carrying out an energy conversion test, a temperature change test, a fatigue life test of a material base metal and a welding joint, and a fatigue fracture characteristic test of the material base metal and the welding joint under fatigue load;
accordingly, the suitability test results include:
energy conversion rule, temperature evolution curve, fatigue life of material base metal and welding joint, and fatigue fracture characteristics of material base metal and welding joint.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710575850.8A CN107525725B (en) | 2017-07-14 | 2017-07-14 | Method and system for detecting fatigue life of aluminum alloy for railway vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710575850.8A CN107525725B (en) | 2017-07-14 | 2017-07-14 | Method and system for detecting fatigue life of aluminum alloy for railway vehicle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107525725A CN107525725A (en) | 2017-12-29 |
| CN107525725B true CN107525725B (en) | 2020-10-16 |
Family
ID=60748937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710575850.8A Active CN107525725B (en) | 2017-07-14 | 2017-07-14 | Method and system for detecting fatigue life of aluminum alloy for railway vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107525725B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109142428A (en) * | 2018-04-13 | 2019-01-04 | 权奥博 | A kind of motor-car orbit strength intelligent checking system |
| CN110907271B (en) * | 2020-01-02 | 2022-06-14 | 中车青岛四方机车车辆股份有限公司 | Method, device and equipment for determining fatigue crack propagation life |
| CN111504818A (en) * | 2020-04-22 | 2020-08-07 | 南京蜂动检测科技有限公司 | Method for detecting fatigue life of aluminum alloy for rail transit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8155940B2 (en) * | 2008-07-30 | 2012-04-10 | GM Global Technology Operations LLC | Methods and systems for predicting very high cycle fatigue properties in metal alloys |
| CN103076246B (en) * | 2013-01-06 | 2014-10-22 | 北京航空航天大学 | Double-shaft high-low cycle complex fatigue tester |
-
2017
- 2017-07-14 CN CN201710575850.8A patent/CN107525725B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107525725A (en) | 2017-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107525725B (en) | Method and system for detecting fatigue life of aluminum alloy for railway vehicle | |
| Klinger et al. | Axle fracture of an ICE3 high speed train | |
| Zerbst et al. | Parameters affecting the damage tolerance behaviour of railway axles | |
| Kaewunruen et al. | Dynamic wheel–rail interaction over rail squat defects | |
| Carboni et al. | Advanced ultrasonic “Probability of Detection” curves for designing in-service inspection intervals | |
| Novosad et al. | Fatigue tests of railway axles | |
| Mandal | On the low cycle fatigue failure of insulated rail joints (IRJs) | |
| Mandal | Ratchetting of railhead material of insulated rail joints (IRJs) with reference to endpost thickness | |
| Moraes et al. | Effect of overlap orientation on fatigue behavior in friction stir linear welds of magnesium alloy sheets | |
| Nejad et al. | An investigation on fatigue behavior of AA2024 aluminum alloy sheets in fuselage lap joints | |
| CN113469388B (en) | Maintenance system and method for rail transit vehicle | |
| Zhao et al. | Probabilistic model for predicting rail breaks and controlling risk of derailment | |
| Zhao et al. | Assessing the economic life of rail using a stochastic analysis of failures | |
| Kanavalau et al. | Evaluation techniques for residual in-use utility of the railway car hopper-batcher bearing structure with a long-term service | |
| Ramzan et al. | Railroads surface crack detection using active thermography | |
| Hu et al. | Structural safety evaluation of a subway bolster based on numerical simulation and experimental test | |
| Pourheidar et al. | Comparison of SIF solutions for cracks under rotating bending and their impact upon propagation lifetime of railway axles | |
| Klinger et al. | 1992 Northeim train crash–A root cause analysis | |
| CN102589863A (en) | Method for judging whether old metal part can be directly reused | |
| Liu et al. | Stress spectrum compilation method and residual life prediction for hot spot position of metro bogie frame under resonance condition | |
| Niu et al. | Stress state grade evaluation method for welded joints of complex structures on railway rolling stock and its application in welded frame | |
| Coulon et al. | Life extension approach focusing on industrial and railway applications | |
| Stepanova et al. | Enhancement of the acoustic-emission method use for diagnostics of rolling stock cast parts | |
| Baek et al. | Reliability assessment and prediction of a fatigue design criterion for the gas-welded joints | |
| RU2010105758A (en) | METHOD FOR CAR REPAIR |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |